Bridging-block for dynamo-electric machines.



- secured in the slot.

UNITED STATES ggENT OFFICE.

FREDERICK WILLIAM YOUNG, OF EAST ORANGE, NEW JERSEY, ASSIGNOR TO CROCKER- WHEELER COMPANY, OF AMPERE, NEW JERSEY, A CORPORATION OF NEW JERSEY.

BRIDGING-BLOCK FOR DYNAMO-ELECTRIC MACHINES.

Specification of Letters Patent.

Patented July 4, 1911.

Application filed April 21, 1910. Serial No. 556,749.

To all whom it may concern:

Be it known that I, FREDERICK YVILLIAM YOUNG, a citizen of the United States of America, and a resident of East Orange, county of Essex, and State of New Jersey, have invented certain new and useful lmprovements in Bridging-Blocks for Dyna- Ino-Electric Machines, of which the follow ing is a specification.

The object of this invention is to provide in combination with a (lyI121 I110-0l0CtI'lC rnachine element, the periphery of which is slotted to receive and contain windings, a bridging-block of simple and inexpensive construction by which each slot is mechanically closed so that the windings will be Magnetic material is suitably incorporated into the bridging block whereby it is made to serve the further object of increasing the surface of the element exposed to the magnetism of the field poles beyond that afforded by the ends of the teeth which lie between the slots of the element.

A further object is to render the n'iagnetic flux sufficiently uniform into and out of the element and yet interrupt the closure su'liiciently to prevent magnetic leakage between the teeth above the windings, and also avoid eddy currents.

A further object is to provide a form of construction which is easy to manufacture and easy to assemble; which will not require insulation from the slot, and which will not be a seat for eddy currents.

In the accompanying sheet of drawings, which forms a part of this application, Figure 1 is a perspective of a bridgingblock embodying my invention. Fig. 2 is a perspective of a modified form of bridging-block. Fig. 3 is an end View of the bridging-block. Fig. 4 is a perspective of a portion of a stator of a dynamo-electric machine with windings secured by the bridging-blocks.

The invention is illustrated in connection with a laminated annular stator with slots in its concave surface, containing windings orcoils B B and constituting the dynamoelectric machine stator element. The application of the invention, however, is not limited to the stator element. The walls of the slots near their mouths and above the windings are inclined, forming dovetailed shaped channels. In the form shown in Fig. l a core consisting of a flat strip of hard press board or fiber C helically wound with iron wire D constitutes the bridging-block which is used to close the slot. At either end a perforation (Z through the core receives and secures the ends of the wire. The block after winding is preferably curved or bent into the shape of a shallow trough so as to have an arcshaped cross-section, thereby enabling it to. lit the slot suliiciently and adapt itself to any irregularities in the slot walls.

In the form shown in Figs. 2 and a. core consisting of a sheet iron strip E is com ployed and is wrapped with paper I before winding the wire thereon. The wire may have a coating of japan or other suitable insulation, thereby avoiding the necessity of insulating the core when of iron, and rendering quite unnecessary the use of insulation between the bridging-block and the slot walls. On account of the high electrical. iinpcdancc. of the helix no short-circuit is atforded between the laminae of the element even the convolutions electrically conla ct therewith.

What I claim new. and desire to secure by Letters Patent of the United States, is-- 1. The combination with a dynamo-electric machine element having coil-containing slots, of elongated slolazlosing bridgingblocks, each consisting ot' a core of magnetic material with an insulating covering and an envclo 'iing helix of magnetic material, sub stantially as described.

The combination with a dynamo-electric nmchine element having coil-containing slots, of elongated slot-closing bridgingblocks, each consisting of an arc-shaped core of maguclic material. and an enveloping helix of magnetic material fitting both sides of the core, substantially as described. 

